About 600 million years ago, life on Earth was pretty much just a homogeneous bunch of simple, soft-bodied species. But in an evolutionary blink of an eye, that all changed. A longstanding geological mystery could explain why our distant ancestors suddenly developed skeletons. »4/19/12 12:46pm 4/19/12 12:46pm

Researchers have discovered 650-to-640 million-year-old sponge fossils at Australia's Flinders Ranges. These fossils predate the oldest known animal fossils by 90 million years and antecede the blossoming of life during the Cambrian Explosion ~524 million years ago. »8/17/10 11:54am 8/17/10 11:54am